• All IHC stains will include a positive control tissue

• Immunohistochemical staining with antibodies to inhibin is of value in the diagnosis of granulosa cell and other sex cord - stromal tumors and in the distinction of these neoplasms from mimics
• 90-100% of adult and juvenile granulosa cell tumors and other sex cord stromal proliferations (including steroid cell tumors) show moderate to strong intensity staining in at least half the cells
• 70-80% of ovarian fibro-thecomas are positive for inhibin
• 10-15% of:
• primary ovarian endometrioid tumors
• primary ovarian transitional cell (Banner) proliferations
• Other primary and metastatic poorly differentiated (undifferentiated) carcinomas can be positive for inhibin but usually show weak staining or staining in less than half of the cells
• Germ cell neoplasms are negative for inhibin
• Caution should be exercised in the interpretation of inhibin positive cells because a wide variety of primary and metastatic ovarian tumors may contain significant numbers of positively staining luteinized cells
• Tissue staining of inhibin does not correlate with serum levels of inhibin
• Inhibin staining is present in normal adrenal gland, adrenocortical adenomas and adrenocortical carcinomas. Paragangliomas* and renal cell carcinoma are negative for inhibin. (*Rare cases may show focal positive)

Submit a formalin-fixed, paraffin-embedded tissue

Formalin-fixed, paraffin-embedded (FFPE) tissue block

FFPE tissue section mounted on a charged, unstained slide

Ambient (preferred)

• Unlabeled/mislabeled block
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• Antibody recognizes 32kD alpha subunit of human inhibin
• Inhibins are peptide hormones that help regulate the pituitary-gonadal feedback system
• Inhibins are selectively expressed by cells of sex cord - stromal derivation

Staining pattern

• Cytoplasmic

References

1. Hildebrandt RH, et. al.: Value of Inhibin in the Identification of Granulosa Cell Tumors of the Ovary. Human Pathol 28:1387-1395, 1997.
2. McCaveeage WG, et. al.: Immunohistochemical Staining of Ovarian Granulosa Cell Tumors with Monoclonal Antibody Against Inhibin. Hum Pathol 28:1034-1038, 1997.
3. Costa MJ et. al.: Inhibin Immunohistochemistry Applied to Ovarian Neoplasm: A Novel Effective Diagnostic Tool. Hum Pathol 28:1247-1254, 1997.